Marketing

Conversion optimization, experimentation, and measuring what marketing actually does.

Aug 7, 202626 min read

A/B Testing in Marketing 2026: Significance, Sample Size, and the Mistakes Almost Everyone Makes

A/B testing without fooling yourself: our own simulations show how peeking pushes the false positive rate from 5% to 32%, and why undersized tests report a true 5% effect as 22.6%.

A/B Testing in Marketing 2026: Significance, Sample Size, and the Mistakes Almost Everyone Makes